Mobile telephones and similar communication devices are rapidly expanding in use and function. Such devices will soon provide Internet access, personal information management, facsimile, and messaging, in addition to telephone communication. This will require a user interface which is more complex, crowded and generally more difficult to use. As a result, the displays associated with such devices are becoming more sophisticated to accommodate these trends. Newer displays have the capability of presenting grayscale and color images, as well as black and white.
These trends cause ever increasing demands on the power supply and have caused increasing challenges to conserve energy especially during periods of standby mode. For example: black and white images displayed in grayscale mode in some instances could increase current consumption as much as 100% over black and white images which are displayed in black and white mode. A further power consumption premium occurs when color image mode is used.
It would, therefore, be advantageous to avoid shade generation during standby and other modes of operation to reduce current consumption. Automatic switching from shade generation, however, will cause image distortion where the user has selected an image which uses color or grayscale mode, thereby detracting from the functionality of this feature.
It is a purpose of this invention to reduce current consumption in a communications device during standby and active operation by disabling shade generation. It is also a purpose of this invention to accomplish the reduction in current consumption while avoiding the distortion of grayscale or color images.
In devices having the capability of displaying grayscale, there is an opportunity to conserve energy when such devices are called upon to display black and white. In such devices, shade generation is employed to obtain the various grayscales. In accordance with this invention, a special program is devised which causes the display data to be searched for the data relating to the current image type to be displayed. When the inquiry results indicate that a grayscale or color graphic is selected, no change in the display mode is directed. If however, the current image is in black and white, then the display driver is programmed to disable the shade generation function.
The microprocessor control unit (MCU) of a mobile phone or other similar communications device is generally programmed to control the display driver of the device. To accomplish the purpose of this invention, the energy conservation software is stored in memory for use by the MCU of the communications device to query the display driver data for an indication of the graphics to be displayed. If black and white graphics are to be displayed, the software adjusts the operation of the display driver to avoid shade generation.
In this manner current consumption may be reduced during standby or normal operation while the feature of using grayscale or color images is preserved.